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Primates (nonhuman)
| fossil_range = | image = Olive baboon.jpg | image_caption = Olive Baboon, Papio anubis | image_width = 280px | regnum = Animalia | phylum = Chordata | classis = Mammalia | infraclassis = Eutheria | superordo = Euarchontoglires | ordo = Primates | ordo_authority = Linnaeus, 1758 | subdivision_ranks = Families | subdivision = * 15, See classification | range_map = Non-human primate range.png | range_map_caption = Range of the non-human primates (green) | range_map_width = 280px }} A primate is a member of the biological order Primates (Latin: "prime, first rank" From Old French or French primat, from a noun use of Latin primat-'', from ''primus ("prime, first rank"). The English singular primate was derived via back-formation from the Latin inflected form. Linnaeus thought this the "highest" order of mammals), the group that contains lemurs, the Aye-aye, lorids, galagos, tarsiers, monkeys, and apes, with the last category including humans. With the exception of humans, who now inhabit every continent on Earth,Humans inhabit every continent if one includes the scientific and meteorological stations in Antarctica. most primates live in tropical or subtropical regions of the Americas, Africa and Asia. Primates range in size from the 30 g (1 ounce) Pygmy Mouse Lemur to the 200 kg (440 pound) Mountain Gorilla. According to fossil evidence, the primitive ancestors of primates may have existed in the late Cretaceous period around 65 mya (million years ago), and the oldest known primate is the Late Paleocene Plesiadapis, c. 55–58 mya. Molecular clock studies suggest that the primate branch may be even older, originating in the mid-Cretaceous period around 85 mya. The Primates order has traditionally been divided into two main groupings: prosimians and simians. Prosimians most closely resemble early proto-primates, and included the lemurs of Madagascar, lorisiforms, Aye-aye and tarsiers. Simians included the monkeys and apes. More recently, taxonomists have created the suborder Strepsirrhini, or "wet-nosed" primates, to include non-tarsier prosimians and the suborder Haplorrhini, or "dry-nosed" primates, to include tarsiers and the simians. Simians are divided into two groups: the platyrrhines ("flat nosed") or New World monkeys of South and Central America and the catarrhine ("narrow nosed") monkeys of Africa and southeastern Asia. The New World monkeys include the capuchin, howler and squirrel monkeys, and the catarrhines include the Old World monkeys (such as baboons and macaques) and the apes. Humans are the only catarrhines that have spread outside of Africa and southeastern Asia, although fossil evidence shows many species once existed in Europe as well. Considered generalist mammals, primates exhibit a wide range of characteristics. Although not all primates live in trees, all species possess some adaptations for an arboreal lifestyle. Locomotion techniques used include: leaping from tree to tree, walking on two or four limbs, knuckle-walking, and swinging between branches of trees (known as brachiation). Primates are characterized by their large brains, relative to other mammals, as well as anatomical adaptations lending to an increased reliance on stereoscopic vision at the expense of smell, the dominant sensory system in most mammals. These features are most significant in monkeys and apes, and noticeably less so in lorises and lemurs. Three-color vision has developed in some primates. Most also have opposable thumbs and some have prehensile tails. Many species are sexually dimorphic, in that males and females have different physical traits, including body mass, canine tooth size, and coloration. Primates have slower rates of development than other similarly sized mammals, and reach maturity later but have longer lifespans. Some species live in solitude, others live in male-female pairs, and others live in groups of up to hundreds of members. The Primates order lies in a tight clustering of related orders (the Euarchontoglires) within the Eutheria, a subclass of Mammalia. Recent molecular genetic research on primates, colugos, and treeshrews has shown that the two species of colugos are more closely related to the primates than the treeshrews, even though the treeshrews were at one time considered primates. These three orders make up the Euarchonta clade. This clade combines with the Glires clade (composed of the Rodentia and Lagomorpha) to form the Euarchontoglires clade. Variously, both Euarchonta and Euarchontoglires are ranked as superorders. Also, some scientists consider Dermoptera a suborder of Primates and call the "true" primates the suborder Euprimates. s, a gibbon (top right) and two orangutans (center and bottom center). The chimp in the upper left is brachiating; the orang at the bottom center is knuckle-walking.]] , a member of the order Primates]] * '''Order Primates' ** Suborder Strepsirrhini: non-tarsier prosimians *** Infraorder Lemuriformes **** Superfamily Cheirogaleoidea ***** Family Cheirogaleidae: dwarf lemurs and mouse-lemurs (31 species) **** Superfamily Lemuroidea ***** Family Lemuridae: lemurs (19 species) ***** Family Lepilemuridae: sportive lemurs (22 species) ***** Family Indriidae: woolly lemurs and allies (18 species) *** Infraorder Chiromyiformes **** Family Daubentoniidae: Aye-aye (1 species) *** Infraorder Lorisiformes **** Family Lorisidae: lorises, pottos and allies (9 species) **** Family Galagidae: galagos (19 species) ** Suborder Haplorrhini: tarsiers, monkeys and apes *** Infraorder Tarsiiformes **** Family Tarsiidae: tarsiers (8 species) *** Infraorder Simiiformes **** Parvorder Platyrrhini: New World monkeys ***** Family Cebidae: marmosets, tamarins, capuchins and squirrel monkeys (56 species) ***** Family Aotidae: night or owl monkeys (douroucoulis) (7 species) ***** Family Pitheciidae: titis, sakis and uakaris (43 species) ***** Family Atelidae: howler, spider and woolly monkeys (24 species) **** Parvorder Catarrhini ***** Superfamily Cercopithecoidea ****** Family Cercopithecidae: Old World monkeys (135 species) ***** Superfamily Hominoidea ****** Family Hylobatidae: gibbons or "lesser apes" (13 species) ****** Family Hominidae: humans and other great apes (7 species) , once considered a prosimian, now considered a haplorrhine]] The order Primates was established by Carl Linnaeus in 1758, in the tenth edition of his book Systema Naturae, for the genera Homo (humans), Simia (other apes and monkeys), Lemur (prosimians) and Vespertilio (bats). In the first edition of the same book (1735), he had used the name Anthropomorpha for Homo, Simia and Bradypus (sloths). In 1839, Henri Marie Ducrotay de Blainville, following Linnaeus and imitating his nomenclature, established the orders Secundates (including the suborders Chiroptera, Insectivora and Carnivora), Tertiates (or Glires) and Quaternates (including Gravigrada, Pachydermata and Ruminantia), but these new taxa were not accepted. In older classifications, the Primates were divided into two superfamilies: Prosimii and Anthropoidea. The Prosimii included all of the prosimians: all of Strepsirrhini plus the tarsiers. The Anthropoidea contained all of the simians. Hybrids Primate hybrids usually arise in captivity, but there have also been examples in the wild. Hybridization occurs where two species' territories overlap; these hybrid zones may be created by humans when animals are placed in zoos or may be due to environmental pressures such as predation. Intergeneric hybridizations, hybrids of different genera, have also been found in the wild. Although they belong to genera that have been distinct for several million years, interbreeding still occurs between the Gelada and the Hamadryas Baboon. Distinguishing features Primates have diversified in arboreal habitats and although they have primitive (unspecialized) body plan, retain many characteristics that are adaptations to this environment. They are distinguished by: * retention of the collar bone in the pectoral girdle; * shoulder joints which allow high degrees of movement in all directions; * five digits on the fore and hind limbs with opposable thumbs and big toes; * nails on the fingers and toes (in most species); * a flat nail on the hallux (in all extant species); * sensitive tactile pads on the ends of the digits; * orbits encircled in bone; * a trend towards a reduced snout and flattened face, attributed to a reliance on vision at the expense of olfaction (most notably in haplorrhines, and less so in strepsirrhines); * a complex visual system with stereoscopic vision, high visual acuity and color vision; * a brain having a posterior lobe and a Calcarine fissure * a large brain in comparison to body size, especially in simians; * differentiation of an enlarged cerebral cortex; * reduced number of teeth compared to primitive mammals; * three kinds of teeth; * a well-developed cecum; * two pectoral mammary glands; * typically one young per pregnancy; * a pendulous penis and scrotal testes; * a long gestation and developmental period and * a trend toward holding the torso upright leading to bipedalism. Not all primates exhibit these anatomical traits, nor is every trait unique to primates. For example, other mammals have collar bones, three kinds of teeth and a pendulous penis, while spider monkeys have greatly reduced thumbs, ruffed lemurs have six mammary glands and strepsirrhines generally have longer snouts and a strong sense of smell. Primates are generalist mammals. In regards to behavior, primates are frequently highly social, with flexible dominance hierarchies. New World species form monogamous pair bonds, and show substantial paternal care of young, unlike most Old World monkeys. Anatomy, physiology and morphology Primates range in size from the Pygmy Mouse Lemur, which is , to the Gorilla, which is . Primates have two forward-facing eyes on the front of the skull; binocular vision allows accurate distance perception, useful for the brachiating ancestors of humans. There is a bony ridge above the eye sockets; this ridge reinforces weaker bones in the face which are put under strain during chewing. Strepsirrhines have a postorbital bar, a bone which runs around the eye socket, to protect their eyes; in contrast, the higher primates, haplorrhines, have evolved fully enclosed sockets. The primate skull has a large domed cranium which is particularly prominent in anthropoids. The cranium protects the large brain, a distinguishing characteristic of this group. The endocranial volume (the volume within the skull) is three-fold greater in humans than in the greatest non-human primate, reflecting a larger brain size. The mean human endocranial volume is 1201 cubic centimetres, it is 469 cm³ in gorillas, 400 cm³ in chimpanzees and 397 cm³ in orangutans. The primary evolutionary trend of primates has been the elaboration of the brain, in particular the neocortex (a part of the cerebral cortex) which is involved with sensory perception, generation of motor commands, spatial reasoning, conscious thought and, in humans, language. While other mammals rely heavily on their sense of smell, the arboreal life of primates has led to a tactile, visually dominant sensory system, a reduction in the olfactory region of the brain and increasingly complex social behavior. Primates generally have five digits on each limb (pentadactyly), with keratin nails on the end of each finger. The bottom sides of the hands and feet have sensitive pads on the fingertips. Most have opposable thumbs, a characteristic primate feature; however opposing thumbs are not limited to this order (opossums, for example, also have them). Thumbs allow some species to use tools. In primates, the combination of opposing thumbs, short fingernails (rather than claws) and long, inward-closing fingers is a relic of the ancestral practice of gripping branches, and has, in part, allowed some species to develop brachiation (swinging by the arms from tree limb to tree limb) as a significant means of transportation. Prosimians have clawlike nails on the second toe of each foot, called toilet-claws, which they use for grooming. The primate collar bone is retained as prominent element of the pectoral girdle; this allows the shoulder joint broad mobility. Apes have more mobile shoulder joints and arms due to the dorsal position of the scapula, broad ribcages that are flatter front-to-back, and a shorter, less mobile spine compared to Old World monkeys (with lower vertebrae greatly reduced, resulting in tail loss in some species). Old World monkeys are unlike apes in that most have tails, and unlike the New World monkeys in that their tails are never prehensile. Only the New World Atelidae family have prehensile tails. Primates show a trend towards a reduced snout. Technically, the distinction of Old World monkeys from New World monkeys depends on the structure of the nose, and the distinction of Old World monkeys from apes depends on the arrangement of their teeth. In New World monkeys the nostrils face sideways; in Old World monkeys, they face downwards. There is a considerably varied dental pattern in primates and although some have lost most of their incisors, all retain at least one lower incisor. In most strepsirhines, the lower incisors and canines form a toothcomb, which is used in grooming and sometimes foraging, and the first lower premolar is shaped like a canine. Old World monkeys also have eight premolars, compared with twelve in New World monkeys. The Old World species are divided into apes and monkeys depending on the number of cusps on their molars; apes have five, Old World monkeys have four. The main hominid molar cusp (hypocone) evolved in early primate history, while the cusp of the corresponding primitive lower molar (paraconid) was lost. Prosimians are distinguished by their immobilized upper lips, moist tip to their nose and forward-facing lower front teeth. The evolution of color vision in primates is unique among most eutherian mammals. While the remote vertebrate ancestors of the primates possessed three color vision (trichromacy), the nocturnal, warm-blooded, mammalian ancestors lost one of three cones in the retina at the time of dinosaurs. Fish, reptiles and birds are therefore trichromatic or tetrachromatic while all mammals, with the exception of some primates and marsupials, are dichromats or monochromats (totally color blind). Nocturnal primates, such as the night monkeys and bush babies are often monochromatic. Catarrhines are routinely trichromatic due to a gene duplication of the red-green opsin gene at the base of their lineage, 30-40 million years ago. Platyrrhines, on the other hand, are trichromatic in a few cases only. Specifically, individual females must be heterozygous for two alleles of the opsin gene (red and green) located on the same locus of the X chromosome. Males, therefore, can only be dichromatic, while females can be either dichromatic or trichromatic. Color vision in strepsirrhines is less understood, however research indicates a range of color vision similar to that found in platyrrhines. Like catarrhines, Howler monkeys (a family of platyrrhines) show routine trichromatism that has been traced to an evolutionarily recent gene duplication. Howler monkeys are one of the most specialized leaf-eaters of the New World monkeys, fruits are not a major part of their diet, and the type of leaves they prefer to consume (young, nutritive, and digestible), are detectable only by a red-green signal. Field work exploring the dietary preferences of howler monkeys suggests that routine trichromacy was environmentally selected for. Sexual dimorphism s (grey) and the female (brown).]] Sexual dimorphism, the variation between individuals of different sex in the same species, is often exhibited in simians; though to a greater degree in Old World species (apes and some monkeys) than New World species. Recent studies involve comparing DNA to examine both the variation in the expression of the dimorphism among primates and the fundamental causes of sexual dimorphism. Primates usually have dimorphism in body mass and canine tooth size along with pelage and skin color. The dimorphism can be attributed to and affected by different factors, including mating system, size, habitat and diet. Comparative analyses have substantiated the sexual selection hypotheses, and have generated a more complete understanding of the relationship between sexual selection, natural selection, and mating systems in primates. Studies are helping to find the relative contribution of the various selective and non-selective mechanisms in sexual dimorphism evolution and expression. These studies have shown that dimorphism is the product of changes in both male and female traits. Ontogenetic scaling, where relative extension of a common growth trajectory occurs, may give some insight into the relationship between sexual dimorphism and growth patterns. Some evidence from the fossil record suggests that there was convergent evolution of dimorphism, and some extinct hominids probably exceeded dimorphism of any living primate. Locomotion , a vertical clinger and leaper, ready to leap to another tree]]Primate species each move variously by brachiation, bipedalism, leaping, arboreal and terrestrial quadrupedalism, climbing or knuckle-walking. Several prosimians are primarily vertical clinger and leapers. These include many bushbabies, all indriids (i.e., sifakas, avahis and indris), sportive lemurs, and all tarsiers. Other prosimians are arboreal quadrupeds and climbers. Some are also terrestrial quadrupeds, while some are leapers. Most monkeys are both arboreal and terrestrial quadrupeds and climbers. Gibbons, muriquis and spider monkeys all use brachiation extensively. Woolly monkeys also sometimes brachiate. Orangutans use a similar form of locomotion called quadramanous climbing, in which they use their arms and legs to carry their heavy bodies through the trees. Chimpanzees and gorillas knuckle walk, and can move bipedally for short distances. Although numerous species, such as the Australopithecines and early hominids, have exhibited fully bipedal locomotion, humans are the only extant species with this trait. Behavior Social systems Richard Wrangham proposed that social systems are best classified by the amount of movement by females occurring between groups. He proposed four categories: *Female transfer systems – females move away from the group in which they were born. Females of a group will not be closely related whereas males will have remained with their natal groups and therefore the close association may be influential in social behavior. The groups formed are generally quite small. This organization can be seen in chimpanzees, where the males, who are typically related, will cooperate in defending the group's territory. Among New World Monkeys, spider monkeys and muriquis use this system. s bathe together in Jigokudani Hot Spring]] *Male transfer systems – while the females remain in their natal groups, the males will emigrate as adolescents. Polygynous and multi-male societies are classed in this category. Group sizes are usually larger. This system is common among the Ring-tailed Lemur, capuchin monkeys and cercopithecine monkeys. *Monogamous species – a male-female bond, sometimes accompanied by juvenile offspring. There is shared responsibility of parental care and territorial defense. The offspring leave the parents' territory during adolescence. Gibbons essentially use this system, although "monogamy" in this context does not necessarily mean absolute sexual fidelity. *Solitary species – often males who defend territories that include the home ranges of several females. This type of organization is found in the prosimians. Orangutans do not defend their territory but effectively have this organization. Other systems are known to occur as well. For example, with howler monkeys both the males and females typically transfer from their natal group upon reaching sexual maturity, resulting in groups in which neither the males or females are typically related. Some prosimians, colobine monkeys and callitrichid monkeys also use this system. s are social animals.]] Primatologist Dr. Jane Goodall, who studied in the Gombe Stream National Park, noted fission-fusion societies in chimpanzees. There is fission where the main group splits up to forage during the day, then fusion when the group returns at night to sleep as a group. This social structure can also be observed in the Hamadryas Baboon, spider monkeys and the Bonobo. The Gelada has a similar social structure in which many smaller groups come together to form temporary herds of up to 600 monkeys. These social systems are affected by three main ecological factors: distribution of resources, group size and predation. Within a social group there is a balance between cooperation and competition. Cooperation comes in the form of allogrooming; whereby ectoparasites are removed and wounds cleaned, food sharing and collective defense against predators or of a territory. Competition is demonstrated by aggression and may come about through availability of food, sleeping sites or mates. Aggression is often used in establishing dominance hierarchies. Interspecific associations Several species of primates are known to associate in the wild. Some of these associations have been extensively studied. In the Tai Forest of Africa, several species coordinate anti-predator behavior. These include the Diana Monkey, Campbell's Mona Monkey, Lesser Spot-nosed Monkey, Western Red Colobus, King Colobus and Sooty Mangabey, which coordinate anti-predator alarm calls. Among the predators of these monkeys is the Common Chimpanzee. The Red-tailed Monkey associates with several species, including the Western Red Colobus, the Blue Monkey, Wolf's Mona Monkey, the Mantled Guereza, the Black Crested Mangabey and Allen's Swamp Monkey. Several of these species are also predated on by the Common Chimpanzee. In South America, but not in Central America, squirrel monkeys associate with capuchin monkeys. This may have more to do with foraging benefits to the squirrel monkeys rather than anti-predation benefits. Cognition and communication Primates are capable of high levels of cognition; some make tools and use them to acquire foods and for social displays; some have sophisticated hunting strategies requiring cooperation, influence and rank; they are status conscious, manipulative and capable of deception; they can recognise kin and conspecifics; they can learn to use symbols and understand aspects of human language including some relational syntax, concepts of number and numerical sequence. Lemurs, lorises, tarsiers, and New World monkeys are reliant on olfactory signals for many aspects of social and reproductive behavior. Specialized glands are used to mark territories with pheromones, which are detected by the vomeronasal organ; this process forms a large part of the communication behavior of these primates. In Old World monkeys and apes this ability is mostly vestigial, and regressed as color vision evolved to become the main sensory organ. Primates also use vocalizations, gestures, and facial expressions to convey psychological state. Development through life stages Primates have slower rates of development than other mammals. All non-human primate infants are breastfed by their mothers and rely on them for grooming and transportation. In some species, infants are also protected and transported by males in the group, particularly males who may be their father. Other relatives of the infant, such as siblings and aunts, may also participate in its care. Most primate mothers cease ovulation while breastfeeding an infant; once the infant is weaned the mother can reproduce again. This often leads to weaning conflict with the infant, who often resist weaning and attempt to continue breastfeeding. Primates have a longer juvenile period between weaning and sexual maturity than other mammals of similar size. During the juvenile period, primates are more susceptible than adults to predation and starvation; they gain experience in feeding and avoiding predators during this period. They also learn social and fighting skills, often through playing. In addition to reaching maturity later, primates have longer lifespans than other similarly sized mammals. Lifespans are generally longer for female primates than males. Diet and feeding , a species of black-and-white colobus]] Primates exploit a variety of food sources. Most primates include fruit in their diets to obtain easily digested carbohydrates and lipids for energy. However, they require other foods, such as leaves or insects, for amino acids, vitamins and minerals. Many primates have anatomical specializations enabling them to exploit particular foods, such as fruit, leaves, gum or insects. For example, leaf eaters such as howler monkeys, black-and-white colobuses and sportive lemurs, have extended digestive tracts to enable them to absorb nutrients from leaves that can be difficult to digest. Marmosets, which are gum eaters, have strong incisor teeth, enabling them to open tree bark to get to the gum, and claws rather than nails, enabling them to cling to trees while feeding. The Aye-aye combines rodent-like teeth with a long, thin middle finger to fill the same ecological niche as a woodpecker. It taps on trees to find insect larvae, then gnaws holes in the wood and inserts its elongated middle finger to pull the larvae out. Some species have additional specializations. For example, the Grey-cheeked Mangabey has thick enamel on its teeth, enabling it to open hard fruits and seeds that other monkeys cannot. The Gelada is the only primate species that feeds primarily on grass. Tarsiers are the most carnivorous primates, exclusively eating insects, reptiles, amphibians and other live animals. Capuchin monkeys, on the other hand, can exploit many different types of food, including fruit, leaves, flowers, buds, nectar, seeds, insects and other invertebrates, and small vertebrates such as birds, bird eggs, lizards, squirrels and bats. The Common Chimpanzee has a varied diet that includes predation on other primate species, such as the Western Red Colobus monkey. Habitat and distribution in Indian city of Agra]] Primates evolved from arboreal animals, and many species live most of their lives in trees. Most primate species live in tropical rain forests. The number of primate species within tropical areas has been shown to be positively correlated to the amount of rainfall and the amount of rain forest area. Making up between 25% and 40% of the frugivore biomass within tropical rainforests, primates play an important role within tropical rain forests by dispersing seeds of many tree species. Some species are partially terrestrial, such as baboons and the Patas Monkey and a few species are fully terrestrial, such as the Gelada and Humans. Non-human primates live in a diverse number of forested habitats in the tropical latitudes of Africa, India, Southeast Asia, and South America, including rainforests, mangrove forests, and montane forests. There are some examples of non-human primates that live outside of the tropics; the mountain-dwelling Japanese Macaque lives in the north of Honshu where there is snow-cover eight months of the year; the Barbary Macaque lives in the Atlas Mountains of Algeria and Morocco. Primates also have a considerable vertical range; the Black Snub-nosed Monkey has been found living in the Hengduan Mountains at altitudes of 4,700 meters (15,400 ft), the Mountain Gorilla can be found at 4,200 metres (13,200 ft) crossing the Virunga Mountains and the Gelada has been found at elevations of up to 5,000 meters (16,400 ft) in the Ethiopian Highlands. Although most species are generally shy of water, a few are good swimmers and are comfortable in swamps and watery areas, including the Proboscis Monkey, De Brazza's Monkey and Allen's Swamp Monkey, which has developed small webbing between its fingers. Some primates, such as the Rhesus Macaque and gray langurs, can exploit human-modified environments and even live in cities. Relationship between human and non-human primates Legal and social status holds a monkey by a rope around her neck, while asking passers-by for money.]] Within the order Primates, human beings are recognized as persons and protected in law by the United Nations Universal Declaration of Human Rights.Article 6: Everyone has the right to recognition everywhere as a person before the law. The legal status of non-human primates (NHPs) is the subject of much debate, with organizations such as Peter Singer's Great Ape Project (GAP) campaigning to award at least some of them legal rights. In June 2008, Spain became the first country in the world to recognize the rights of some NHPs when its parliament's cross-party environmental committee urged the country to comply with GAP's recommendations, which are that the right to life, the protection of individual liberty, and the prohibition of torture be extended to chimpanzees, bonobos, orangutans, and gorillas. ' manual dexterity is one reason they can assist quadraplegic human beings.]] Many species of NHP are kept as pets or zoo exhibits by human beings, or used as model organisms in laboratories or in space missions. They also serve as so-called "service animals" for disabled human beings. Capuchin monkeys can be trained to assist quadraplegic humans; their intelligence, memory, and manual dexterity allows them to perform tasks that a quadraplegic is physically unable to do. Non-human primates can be carriers of viruses such as Herpesviridae, Poxviridae, measles, ebola, rabies, the Marburg virus and viral hepatitis. Some of these are zoonotic diseases that can also be transmitted to humans, most notably the potentially fatal Herpes B Virus. Human activities indirectly threaten numerous primate species with extinction. More direct threats from humans include monkey drives to protect agriculture. Animal testing Thousands of non-human primates are used around the world in research because of their psychological and physiological similarity to human beings. In particular, the brain and eyes of NHPs more closely parallel human anatomy than that of any other group of animals. NHPs are commonly used in preclinical trials, neuroscience, ophthalmology studies, and toxicity studies. Rhesus Macaques are often used, as are other Macaques, African green monkeys, chimpanzees, baboons, squirrel monkeys, and marmosets, both wild-caught and purpose-bred. In 2004, the European Union used around 10,000 NHPs; in 2005 in Great Britain, 4,652 experiments were conducted on 3,115 NHPs. In the same year, GAP reported that 1,280 of the 3,100 NHPs living in captivity in the United States were used for experiments. European groups such as the European Coalition to End Animal Experiments are seeking a ban on all NHP use in experiments as part of the European Union's review of animal testing legislation. As pets or zoo exhibits GAP estimates that around 3,000 NHPs — which are openly advertised by dealers in exotic animals — live in captivity in the United States, while the Humane Society of the United States puts the figure much higher, at around 15,000. The expanding Chinese middle class has also increased demand for NHPs as exotic pets in recent years. Although NHP import for the pet trade was banned in the U.S. in 1975, smuggling still occurs along the United States–Mexico border, with prices ranging from $3000 for monkeys to $30,000 for apes. Conservation The International Union for Conservation of Nature (IUCN) lists more than a third of primates as critically endangered, endangered or vulnerable. Common threats to primate species include deforestation, forest fragmentation, primate crop raiding, and primate hunting for use in medicines, as pets, and for food. Large-scale tropical forest clearance is widely regarded as the process that most threatens primates. More than 90% of primate species occur in tropical forests. The main cause of forest loss is clearance for agriculture, although commercial logging, subsistence harvesting of timber, mining, and dam construction also contribute to tropical forest depletion. In Indonesia large areas of lowland forest have been cleared to increase palm oil production, and one analysis of satellite imagery concluded that during 1998 and 1999 there was a loss of 1,000 Sumatran Orangutans per year in the Leuser Ecosystem alone. ]] Primates with a large body size (over 5 kg) have an increased extinction risk due to their increased profitability to poachers compared to smaller primates. They also have a slow life history with an increased sexual maturity age and a longer period between births. Populations therefore have a slower recovery time after the loss of members to poaching or the pet trade. In some African cities estimates suggest that half of all protein consumed in urban areas comes from the bushmeat trade. Endangered primates such as guenons and the Drill are hunted at levels that far exceed sustainable levels. This is due to their large body size, ease of transport and profitability per animal. As farming encroaches on forest habitats, primates feed on the crops, causing the farmers large economic losses. Primate crop raiding gives locals a negative impression of primates, hindering conservation efforts. Madagascar, home to five endemic primate families, has experienced the greatest extinction of the recent past; since human settlement 1,500 years ago, at least eight classes and fifteen species have become extinct due to hunting and habitat destruction. Among the primates wiped out were Archaeoindris (a lemur larger than a silverback gorilla) and the families Palaeopropithecidae and Archaeolemuridae. In Asia, Hinduism, Buddhism, and Islam prohibit eating primate meat; however primates are still hunted for food. Some smaller traditional religions allow the consumption of primate meat. The pet trade and traditional medicine also increase demand for illegal hunting. The Rhesus Macaque, a model organism, was protected after overtrapping threatened its numbers in the 1960s; the program was so effective that the macaques are now seen as a pest throughout their range. In Central and South America forest fragmentation and hunting are the two main problems for primates. Large tracts of forest are now rare in Central America. This increases the amount of forest vulnerable to edge effects such as farmland encroachment, lower levels of humidity and a change in plant life. Movement restriction results in a greater amount of inbreeding, which can cause deleterious effects leading to a population bottleneck, whereby 50% of the population is lost. Cross River Gorilla]] There are 21 critically endangered primates, eight of which have remained on the IUCN's "The World's 25 Most Endangered Primates" list since the year 2000: the Silky Sifaka, Delacour's Langur, the White-headed Langur, the Gray-shanked Douc, the Tonkin Snub-nosed Langur, the Hainan Black Crested Gibbon, the Cross River Gorilla and the Sumatran Orangutan. Miss Waldron's Red Colobus was recently declared extinct when a report from 1993–1999 could find no trace of the subspecies. However, hunters have killed individuals since then but its prospects remain bleak. Groups *Baboons *Bonobos *Chimpanzees *Gorillas *Monkeys See also *Arboreal theory *Primatology Notes External links * Primate Info Net * Primate Research Institute, Kyoto University * High-Resolution Cytoarchitectural Primate Brain Atlases * EUPRIM-Net: European Primate Network * PrimateImages: Natural History Collection Category:Primates Category:Mammals